hi guys,

how can I figure out which 02 harness is which? I had my harness tagged but over time, the tags came off and now i'm not sure which is which. I think i have them hooked up right, but I'm not sure. I scanned the car and I was getting funny 02 readings (lazy fluctuations, sticking at static voltages) and little pops in the exhaust once I got into closed loop. I had issues with a busted 02 sensor before, and i had similar symptoms -- the car would bog down, stumble, etc.

Is there a way to figure it out from probing the wires under the car? does anything happen if the 02 sensors are crossed that would be similar to what I'm describing above?

thanks!

 

im not certain but would assume if you unhooked one of the connecters you should be able to see which bank is fluctating


Posted from Camaroz28.com App for Android

 

the thing is both are fluctuating so slowly that i can't tell which is which! its very frustrating. the 02 sensors are relatively new too...

 

My thought is if one is unhooked it shouldnt send a signal given it will read the one that is still hooked up it will tell you bank one or bank two. (I am on phone so also dont know what year your car is so I am assuming its the front o2 s that you think may be swapped). May also want to check the fuse for the heater on them. If you are scanning live data you can key on(engine off) and watch the volts move as they heat. I really am not sure if my theory will work but its what I would try until someone who truly knows gives a reccomendation


Posted from Camaroz28.com App for Android

 

Look at Shoebox's harness photo to see what other wires the left and right O2's are grouped with:

1995 Z28 A4 Engine Harness

Passenger side O2 is bundled with the starter, knock sensor and block ground, driver side O2 is bundled with the oil pressure sensor and the foil wrapped harness that goes forward to the MAF, coil, ICM, etc.

If you accidentally switch the O2 sensors harness connections, the PCM will lose control of the A/F ratio on both banks of the engine.

 

Unplug the driver side O2 sensor and see which side sets a code. If the passenger side displays a dead O2 then you have the harness backwards.

 

Ditto on what 97WS6SCharged said.